1. Field of the Invention
The present invention relates to a door opening trim weather strip for providing a seal between a door opening portion and a door of a motor vehicle.
2. Description of Related Art
FIG. 1 shows a partially cut away side view of a motor vehicle. To provide a seal between a door opening portion 10 of a vehicle body and a door 12, a door opening trim weather strip (not shown) is attached to the door opening portion 10. One example of a conventional door opening trim weather strip is shown in FIG. 2.
As shown, a door opening trim weather strip 14 includes a trim portion 16 and a tubular seal portion 18. The door opening trim weather strip 14 is attached to the door opening portion 10 by inserting a flange 20 provided in the door opening portion 10 into an interior of the trim portion 16.
When the door 12 is closed, the tubular seal portion 18 of the door opening trim weather strip 14 contacts and presses a protruding part 22, for example, of the door 12 to seal between the door opening portion 10 and the door 12, as disclosed in Publication of Japanese unexamined patent application No. 2000-142266, on pages 2 to 3, and in FIG. 1, for example.
The trim portion 16 has a U-shaped cross-section, and has flange holding lips for holding the flange 20. The flange holding lips respectively project into the interior of the trim portion 16.
The flange holding lips include outer holding lips 24 extending from an outer side wall 26 of the trim portion 16 and an inner holding lip 28 extending from an inner side wall 30 of the trim portion 16. To hold the flange 20 securely irrespective of variations in the flange thickness, the outer holding lips 24 are made short, whereas the inner holding lip 28 is made long. Publication of Japanese unexamined patent application No. 2000-25535, on pages 3 to 4, and in FIG. 3, for example, discloses that three short outer holding lips and one long inner holding lip are provided for facilitating the production thereof, and ensuring a low inserting load of the flange upon mounting on the flange.
Where the door opening trim weather strip 14 having one inner holding lip 28 is attached along corners in the vehicle body, the inner flange holding lip 28 deforms to approach the inner side wall 30 due to the bending of the trim portion 16, to define a gap between the inner flange holding lip 28 and the flange 20. Consequently, the door opening trim weather strip 14 may tilt sidewardly of the flange 20.
The number of body panels which are joined to form flanges varies according to the portions of the vehicle body. For example, in some portions, one or two body panels form the flange, and in other portions, five body panels form the flange. Consequently, the flange thickness greatly varies in the vehicle body.
To mount the door opening trim weather strip on the flanges having various thickness, as described above, it is necessary to enlarge the width of the interior of the trim portion having a generally U-shaped cross-section, that is the distance between facing side walls of the trim portion, and increase the length of the inner flange holding lip 28.
Upon mounting the door opening trim weather strip on the flanges having various thickness, there has been used a roll forming method of first spreading the side walls of the trim portion 16 to enlarge the width of an open mouth thereof, and clamping the spread side walls to narrow the width of the open mouth thereof after setting the flange 20 into the interior of the trim portion 16.
In the roll forming method, the door opening trim weather strip 14 must be provisionally set on the flange 20 for positioning prior to the clamping of the side walls. To this end, conventionally, two inner flange holding lips are provided. The flange 20 is first held by a bottom-side inner flange holding lip and the outer flange holding lip 24 for positioning on and provisionally setting on the flange 20. Then the side walls of the trim portion 16 are clamped by means of a pair of clamping rollers.
Where the open mouth of the trim portion 16 is enlarged in the roll forming method; it is necessary to make the inner flange holding lip 28 close to the open mouth of the trim portion 16 long. On the other hand, where, as shown in FIG. 3, two long inner flange holding lips 28 and 32 are provided, and, as shown in FIG. 4, the flange 20 is formed by welding a plurality of body panels to each other, the two inner holding lips 28 and 32 bend toward the inner side wall 30 upon inserting the flange 20 into the interior of the trim portion 16. Consequently, the inner flange holding lip 28 close to the open mouth of the trim portion 16 contacts and pushes the inner flange holding lip 32 provided near the bottom of the trim portion 16 so as not to bend sufficiently, thereby increasing friction between the flange 20 and the inner flange holding lip 28 so as to undesirably increase an inserting load of the flange 20.
To prevent the contacting of the inner flange holding lips 28 and 32, conventionally, the inner side wall 30 is made high to enlarge the distance between the inner flange holding lips 28 and 32.
Where the inner side wall 30 is made high, however, a core member 34 such as a sheet metal, etc. which is embedded inside the trim portion must be made high, too. Consequently, the weight of a polymer material such as rubber, synthetic resin, etc. for composing the trim portion 16, and the weight of the core member 34 both increase, and the producing costs of the trim portion also increase.
As described above, in the roll forming method, the inner side wall 30 must have the inner flange holding lip 32 near the bottom thereof for positioning and provisionally setting the door opening trim weather strip 14 on the flange 20. In the roll forming method, it is unnecessary to consider an inserting load of the flange 20 into the trim portion 16, but it is necessary to increase a pulling load of the trim portion 16 off the flange 20 irrespective of variations in the thickness of the flange 20 so that the trim portion 16 is difficult to be pulled off the flange 20.